Optimize DB requests in project list, job list, and other endpoints

cvat/apps/engine/serializers.py

@@ -1360,10 +1360,14 @@ class Meta:
 
     def to_representation(self, instance):
         response = super().to_representation(instance)
-        task_subsets = {task.subset for task in instance.tasks.all()}
-        task_subsets.discard('')
+
+        task_subsets = {task.subset for task in instance.tasks.all() if task.subset}
+        task_dimension = next(
+            (task.dimension for task in instance.tasks.all() if task.dimension),
+            None
+        )
         response['task_subsets'] = list(task_subsets)
-        response['dimension'] = getattr(instance.tasks.first(), 'dimension', None)
+        response['dimension'] = task_dimension
         return response
 
 class ProjectWriteSerializer(serializers.ModelSerializer):

cvat/apps/engine/views.py

@@ -1705,8 +1705,18 @@ class JobViewSet(viewsets.GenericViewSet, mixins.ListModelMixin, mixins.CreateMo
     mixins.RetrieveModelMixin, PartialUpdateModelMixin, mixins.DestroyModelMixin,
     UploadMixin, DatasetMixin, CsrfWorkaroundMixin
 ):
-    queryset = Job.objects.select_related('assignee', 'segment__task__data',
-        'segment__task__project', 'segment__task__annotation_guide', 'segment__task__project__annotation_guide',
+    queryset = Job.objects.select_related(
+        'assignee',
+        'segment__task__data',
+        'segment__task__project',
+        'segment__task__annotation_guide',
+        'segment__task__project__annotation_guide',
+        'segment__task__source_storage',
+        'segment__task__target_storage',
+        'segment__task__organization',
+        'segment__task__project__organization',
+        'segment__task__owner',
+        'segment__task__project__owner',
     ).annotate(
         Count('issues', distinct=True),
     ).all()

cvat/apps/iam/permissions.py

@@ -48,6 +48,13 @@ def get_organization(request, obj):
 
             raise exc
 
+        if not organization_id:
+            return None
+
+        if org := getattr(obj, 'organization', None):
+            if isinstance(org, Organization):
+                return org
+
         try:
             return Organization.objects.select_related('owner').get(id=organization_id)
         except Organization.DoesNotExist: